The changes relaxed some harsh measures that dated back to the time of Communist China’s founding father, Mao Zedong. Human rights groups said the changes to the one-child policy were disappointingly limited. But they praised the decision to get rid of labour camps as a step in the right direction for the eight-month-old government of President Xi Jinping.

The policy changes were announced after a meeting of top Communist Party officials, who also grappled with reforms designed to revitalize the country’s slowing economy and gave Xi considerable new powers over national security and economic decisions.

The new family-planning policy states that if either member of a couple is an only child, the couple may have two children. The change means that most young Chinese couples can now have two children, if they wish.

Couples where both partners are only children — common in Chinese cities — have long been allowed to have a second child, however, and rural families are also allowed to do so if their first child is a girl. Many urban couples prefer to have only one child because the rising cost of housing and education make having multiple children so difficult.

For all these reasons, demographers say, the relaxing of the policy is unlikely to cause a significant rise in the country’s 1.3 billion population. “There could be a slight rise, but this policy will not cause a dramatic growth in the birth rate,” said Li Jianmin, a population professor at Nankai University.

China enacted the controversial one-child policy in 1980, in an effort to rein in runaway population growth. Internal debate about relaxing the policy has intensified in the face of an aging population and looming shortage of labour.

Human rights groups, who have consistently exposed forced abortions, infanticide and involuntary sterilizations being propagated under the policy, had wanted the policy abolished altogether.

“One-child policy reform really falls short,” said Nicholas Bequelin of Human Rights Watch in Hong Kong. “The whole system needs to be dismantled. What they’re doing is just tinkering with it, allowing one specific category of people to have two children. And it’s being done mostly for demographic reasons . . . and not because the system is abusive and generates so much pain for so many.”

The one-child policy reshaped Chinese society — with birthrates plunging from 4.77 children per woman in the early 1970s to 1.64 in 2011, according to estimates by the United Nations — and contributed to the world’s most unbalanced sex ratio at birth, with baby boys far outnumbering girls.

The “reeducation through labour” system was introduced under Mao in the 1950s as a way to deal with political enemies. Statistics are hard to come by, but according to the government, 160,000 people were held in 350 such facilities throughout China in 2008.

Friday’s policy document, released three days after the conclusion of the Third Plenum of the 18th Central Committee of the Communist Party, was drafted under the direct supervision of Xi and appeared to further consolidate his powers. A new State Security Committee is to be established, with control over both domestic security and foreign policy, and is likely to report directly to the president.

“State security and social stability are the preconditions for reform and development,” Xi said, according to state television. “Now China is facing double pressure: externally to safeguard state sovereignty, security and the interest of development; internally to maintain political safety and social stability. All types of foreseeable and unforeseeable risks are clearly on the rise.”

Analysts say the new committee could bear some similarities to the U.S. National Security Council. It is partly an attempt to bring greater coordination and clarity to China’s sometimes disjointed foreign policy, and also to strengthen Xi’s control over internal security, they say. A newly created team to hasten economic reforms also gives Xi more power to push through measures that may face internal opposition from powerful vested interests.